This video describes and demonstrates a simple, single-band, low-power, electronic transmit / receive switch using PIN diodes an a quarter-wavelength RF transmission line. A lumped element equivalent of the 1/4 wavelength line is discussed and built into a PIN diode based T/R switch, and the operation is demonstrated on the oscilloscope. This video builds upon a few prior videos, listed here:
#118: Basics of PIN Diodes:
https://www.youtube.com/watch?v=XpYsCM_Wf50
#82: Using Diodes as Switches:
https://www.youtube.com/watch?v=YBNIq_d56sA
#62: Tracking generator showing quarter wavelength transmission lines:
https://www.youtube.com/watch?v=bbnllGycQws
The notes for this video can be found here:
http://www.qsl.net/w2aew/youtube/TRswitch.pdf